Why did renaming "parent" category messed up child categories?

I had a category called "Locations" and underneath as children locations like "Illinois", "Michigan" etc.

I renamed the Locations category to "Orte" and my sub categories are gone from the list of available categories (I am looking at the categories view that shows all categories and allows them to be edited. The sub categories are completely removed from that list, i.e. they do not show up as root categories after the change either